Carburetors



Nov. 8, 1966 Filed May 1o, 1963 J. BIVER CARBURETORS Fig.:

5 Sheets-Sheet l Nov. 8, 1966 J. BNER 3,284,066

CARBURETORS y Filed May 10, 1965 5 Sheets-Sheet 2 United States Patent O3,284,066 CARBURETORS Jean Biver, Paris, France, assignor to Societe duCarburateur Zenith, Lyon, France, a company of France Filed May 10,1963, Ser. No. 279,443 Claims priority, application France, May 17,1962, 897,902 2 Claims. (Cl. 261-70) A certain number of essentials arerequired of modern carburetors and, from these, certain conditionsresult which are fairly readily reconciliable.

Thus, the need to avoid the phenomena due to boiling of the petrol(percolation) leads to the necessity of protecting the carburetioncircuits as much las possible from the ow of heat coming from theengine.

The ever decreasing space available under the bonnets which cover theengines of modern motor cars results in carburetors being made off asllow height and as compact as possible.

The desire for constancy of characteristics as between carburetors ofthe same manufacturing type or series necessitates very great m-achiningprecision.

Finally, for the sake of reduction of cost, the greatest possiblesimplicity of manufacture and assembly is necessary.

It is an object of the invention to provide a carburetor which will meetthese various requirements in a satisfactory manner.

According to the invention there is provided a carburetor comprisingamain body containing a constant-'level fuel chamber of the customaryform, -a cover for closing said main body, and a block, hereinaftercalled the carburetion block, which is separate from the main body `andwhich provides the whole, or at least almost the whole, of a system ofducts and orifices through which fuel passes for the carburetion of airdrawn lin by the engine. The canburetion block bears on the main bodyalong a horizontal plane and is adapted either to t the main body or torest on the perimeter of this body. Although substantialy the whole ofthe carburetion system is formed in t-he block, there is -an exceptionin the case of the slow-running duct, which extends as far las thethrottle valve.

With such 'an arrangement the carburetion block can be machinedseparately and the arrangement aftords many advanatges for theyachievement of the various conditions lset forth above.

Preferably, the canburetion block adjoins a section of the main emulsionand yair-mixing passages, and thus facilitates the provision of aninsulating gasket between the block land a neck portion by means yofwhich the carburetor is connected to an engine. Such a -gasket outs 'oithe flow of lheat from the engine through the wall of the neck portion.

Further features of the invention will appear from the description whichfollows, which is given with reference to the accompanying drawings landby way of example only, it being understood that both the featuresdescribed a-nd those appearing from the drawing come within the scope ofthe invention.

In the drawings:

FIGURES 1 to 6 show one constructionai form'of the invention, 4asapplied to -a single-body carburetor. In these figures:

FIGURE 1 is a longitudinal section showing in external view, thecarburetion block which constitutes a part off this form of carburetor.

FIGURE 2 is a plan view of the block of FIGURE 1;

FIGURE 3 is a view of the block from below;

FIGURE 4 is a plan view of a main body which constitutes part of thecarburetor;

3,284,066 Patented Nov. 8, 1966 ice FIGURE 5 is a vertical section ofthe carburetor as a whole and FIGURE 6 is a partial section at rightangle to the plane of FIGURE 5; it shows -diagrammatically parts of theslow-running circuit Which have been off-set angularly for illustration.

The carburetor shown in FIGS. 1 to 6 isof the downdraft type. Itcomprises a main body 1 which terminates at the top in the horizontalplane A-A (FIGURE 1) ywith la horizontal rim 1b and which contains thevusual constant-level chamber 2 for the fuel. The main body issurmounted by the cover or top 4 which is connected to the main body inthe horizontal plane A--A and which carries the air intake S equippedwith an a-ir choke or strangler 6. The lower horizontal surrface of thecover is designated 4b. The main body bas at the lower part thereof, aneck section 7 intended to be connected to the induction manifold oftheengine ian-d containing `a throttle valve 8i. The controls for the airchoke 6 and for the throttle valve I8 are not shown in detail since theymay be constructed in any one of Ithe usual ways.

In the main body 1 is a so-called carburetion block 9 which forms one'of the principal features of the present invent-ion. This blockcontains the whole of the ducts and orifices through which fuel comingfrom the constantlevel chamber 2 enters the system which serves tocarburet air intering through the intake 5. The block 9 includes atubular portion 9a which serves for the passage of air to be carbureteda-nd is disposed between the portion which provides the air intake 5 andthe neck section 7. The portion 9a rests, by means of its annularsurface 9b, on Ia bearing surface 1a of the main body-:and terminates atthe top in the common plane A-A of main cup body 1 and the cover 4. A-ninsulating gasket 10` is interposed between the bearing surface 1a ofthe main body and the annular surface 9b of the block.

The block 9 is separate from the rnain body 1 and the cover 4 yand cantherefore be machined separately before being assembled with the cover 4and the main body.

Fuel is conveyed through a pipe 11 to -an orice 12 provided in the seatof the needle valve 13 which regulates the admission of fuel into theconstant-level chamber and which, for this purpose, is actuated in theusual manner by a float 14. 'I'Ihis oat comprises two elements 14 and14a which are pivotally lmounted on the block 9 at 15 and 15a andtherefore Iadjoin the block.

Bores are drilled in the block 9, which bores are oblique in the form ofembodiment illustrated and in which a main jet 16 and a slow-running jet18 are arranged inthe usual manner. The main jet 16 is followed by anatomizer 17 (FIGURE 5), which has lateral holes 17a through which entersair coming from a calibrated hole 23. Air entering through the holes 17aserves to form the main emulsion with fuel passing through the jet 16.This emulsion escapes through the outlet tube 19, the end of which iscut in the manner of a whistle and opens into the diffusion venturimember or cone 20 which is integral with the block 9 and is locatedcoaxially with the tubular portion 9a. As will be seen in FIGURE 2, theventuri member 20 is carried by an arrn 21 of the block which has acalibrated orifice 22 formed therein for degassing ventilation, inaddition to the orice 23 which, as previously mentioned, serves for theadmission of air for forming the emulsion in the atomizer 17. Thepresence of the arm 21 means that the tubular portion 9a is notperfectly circular in form, as shown in FIGURES 2 and 3, but this is ofno importance from the point of View of the operation of the carburetor.

The carburetor includes a slow-running devicewhich is showndiagrammatically in vertical section in FIGURE 6 and comprises a duct 24in the block 9, extending from the slow-running jet 18, a duct 25 in thecover 4 and a duct'26"'in the main 'body-1, the duct '26 terminating,downstream of the throttle valve, in an outlet orifice 27 controlledl byan adjusting screw 28. The duct 26 may be provided with a progressionvoradvance orifice 29 opening into the zone at which the throttle member 8rests in the closed `position thereof. A calibrated hole 30 -is providedin the cover 4 and opens inside the air intake to afford communicationbetween the outside air and the upper part of the slow-running duct 26,so as to avoid siphon effects.

In addition to the main carburetion ducts and the other elements whichhave been described, the block 9 may be provided also with other deviceswhich are usually provided in carburetors, such as a power enrichingdevice and an accelerating pump, the principle of the invention being toprovide on the block, separate from the main body and the cover, themaximum number of elements and devices serving for carburetion. Thus, inFIGURE 2 there is shown at 22a the outlet pipe of an accelerating `pumpwhich is mounted in the block 9 at 22h.

In the embodiment illustrated, the block 9 is fixed to the insidesurface of the cover 4 before the latter is mounted on the main body 1.The fixing of the block 9 to the cover 4 is effected by using as aconnecting screw, a threaded member 31 which contains the needle valve13. This member 31 has six operating faces 31a which lare located belowthe block 9 and is screwed by means of its upper threaded end into theportion 11a of the cover 4 which provides a continuation of the petrolinlet duct 11. The assembly constituted by the cover 4 and thecarburetion block 9 is assembled with the main body 1 by fitting theblock 9 into the body 1 and the cover 4 is then fixed to the main body 1by any suitable means, such as screws. K

It will be noted that the described arrangement of the block enables agasket 10, which is a relatively thick insulating gasket, to be'interposed between the block 9 and the tubular neck portion 7 which isconnected to the engine. Thetransmission of heat from the engine to thecarburetion ducts by conduction through the metal walls is checked. Itis thus possible to combat the phenomena of boiling of the fuel in thecarburetion system and thus to avoid the drawbacks which followtherefrom. It will ybe noted that in the embodiment shown in FIGURES 1to 6, the plane of the gasket disposed between the carburetion block 9and the main body 1 is below the level of the fuel in the constant-levelchamber 2, which level is itself below the plane of the joint A-Abetween the cover and the main body.

Many other constructional forms of the invention may be devised withoutdeparting from the scope thereof, as defined by the appended claims.

What'I claim is:

1. A carburetor having an induction passage comprising a main body, aconstant level fuel chamber and a first section of said inductionpassage in said mainbody, a horizontal rim at the upper end of said mainbody above the fuel level in said fuel chamber, a horizontal bearingsurface provided in said main body below the fuel level and surroundingthe upper end of said first induction passage section, a carburetionblock in said main body separate therefrom and providing a secondsection of said induction passage coextensive with said first section,fuel passages in said block for connecting said fuel chamber with saidsecond induction passage section, Vahorizontal annular surface providedinsaid block around the lower end of said second induction passagesection, an insulating gasket interposed between said bearing surface ofthe main body and said annular surface of said block, said block havinga horizontal top surface situated in the same plane as said rim, a coverproviding a third section of said induction passage coextensive withsaid first and second sections and forming an air intake to saidcarburetor said cover having a lower horizontal surface contacting bothsaid rim of said body and said top surface of said block.

2. A carburetor according to claim 1 wherein the carburetion blockincludes an oblique emulsion outlet duct projecting into the secondinduction passage section.

References Cited by the Examiner UNITED STATES PATENTS 3,076,639 2/ 1963Szwargulski et al. 261-72 X 3,089,685 5/ 1963 Hennemann et al, 261-72 X3,109,043 10/ 1963 Carlson et al. 261-72 X FOREIGN PATENTS 501,651 2/1939 Great Britain.

HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner.

1. A CARBURETOR HAVING AN INDUCTION PASSAGE COMPRISING A MAIN BODY, ACONSTANT LEVEL FUEL CHAMBER AND A FIRST SECTION OF SAID INDUCTIONPASSAGE IN SAID MAIN BODY, A HORIZONTAL RIM AT THE UPPER END OF SAIDMAIN BODY ABOVE THE FUEL LEVEL IN SAID FUEL CHAMBER, A HORIZONTALBEARING SURFACE PROVIDED IN SAID MAIN BODY BELOW THE FUEL LEVEL ANDSURROUNDING THE UPPER END OF SAID FIRST INDUCTION PASSAGE SECTION, ACARBURETION BLOCK IS IN MAIN BODY SEPARATE THEREFROM AND PROVIDING ASECOND SECTION OF SAID INDUCTION PASSAGE COEXTENSIVE WITH SAID FIRSTSECTION, FUEL PASSAGES IN SAID BLOCK FOR CONNECTING SAID FUEL CHAMBERWITH SAID SECOND INDUCTION PASSAGE SECTION, A HORIZONTAL ANNULAR SURFACEPROVIDED IN SAID BLOCK AROUND THE LOWER END OF SAID SECOND INDUCTIONPASSAGE SECTION, AN INSULATING GASKET INTERPOSED BETWEEN SAID BEARINGSURFACE OF THE MAIN BODY AND SAID ANNULAR SURFACE OF SAID BLOCK, SAIDBLOCK HAVING A HORIZONTAL TOP SURFACE SITUATED IN THE SAME PLANE AS SAIDRIM, A COVER PROVIDING A THIRD SECTION OF SAID INDUCTION PASSAGECOEXTENSIVE WITH SAID FIRST AND SECOND SECTIONS AND FORMING AN AIRINTAKE TO SAID CARBURETOR SAID COVER HAVING A LOWER HORIZONTAL SURFACECONTACTING BOTH SAID RIM OF SAID BODY AND SAID TOP SURFACE OF SAIDBLOCK.